Examine source code of Youtube UnNag

{
  "manifest_version": 2,
  "name": "ytUnNag",
  "version": "1.6resigned1",
  "description": "Invalidates Google nag screen on Youtube",
  "icons": {
    "48": "icons/ytUnNag-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://*.youtu.be/*"
      ],
      "js": [
        "ytUnNag.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a7a2dc6-ecc3-4b22-97b0-522d746c7d67}"
    }
  }
}